Lesson Plan Details

Bats (GMHDRNC)

Topic

Wildlife - Mammals

Summary

Bats exhibit all the characteristics of mammals: they have hair and give birth to live young who are fed on milk from mammary glands. However, bats take it to the skies as the only true flying mammals. Learn the basic biology of bats as well as their physical adaptations for survival.

Nearly 1,000 species of bats exist with 42 species in the United States and 18 of those in Arkansas. They can vary in size from just over two grams to more than two pounds. Though not found in the Americas, the flying fox bats have wingspans of up to six feet.

Procedure

Discuss the characteristics that define mammals.

Using a diagram or picture, point out some of the unique features of bats.

Bats belong to the mammalian order Chiroptera, which means “hand wing.” The bones in a bat’s wings are actually the same as those in the human arm and hand. In the bat, though, the finger bones have been elongated and connected by a double membrane of skin to form the wing.

Female bats reproduce once a year. Breeding is usually in autumn, but the sperm is held until spring for fertilization. Gestation lasts a few weeks and bats usually give birth to one offspring per year, though some species have three to four at a time. Baby bats develop rapidly and begin flying two to five weeks after birth.

Discuss some of the behavioral specializations of bats such as echolocation, hibernation or migration.

Bats are nocturnal and hunt mostly at night. While they have relatively good eyesight, most depend on their highly developed echolocation to capture prey in the dark. The creatures are able to “see” objects in front of them by emitting up to 200 high frequency pulses of sound per second and listening for the rebound. Bats can detect objects as small as a piece of thread in their path. Once the animal has honed in on its prey (mostly insects), the bat will either catch it in its mouth or scoop up several insects using their wings and tail.

Most bat species spend winters in caves and move to trees or buildings in the summer. Some bats, however, spend their lives entirely in trees, moving to hollow trees in cold weather. Some bat species migrate hundreds of miles to and from winter roosts and generally return to the same cave throughout their lifetimes.

Bat – flying mammals of the order Chiroptera that have modified forelimbs that serve as wings and are covered with a membranous skin extending to the hind limbs

Chiroptera – order in which bats are classified

Echolocation – system used by dolphins, bats and other animals to locate objects by emitting high-pitched sounds that reflect off the object and return to the animal's ears or other sensory receptors

Hibernation – an inactive state resembling deep sleep in which certain animals living in cold climates pass the winter; body temperature is lowered and breathing and heart rates slow down; protects the animal from cold and reduces the need for food during the season when food is scarce

Mammal – any of a class of higher vertebrates, including man, that produce milk for their young, have fur or hair, are warm-blooded and, with the exception of the egg-laying monotremes, bear young alive

Migration – the regular, periodic movement of an animal population from one area to another, usually because of a change in temperature, food supply or the amount of daylight, and is often undertaken for breeding; mammals, insects, fish and birds migrate